Mental Health trigger warning.

Ok so we're both 18, seniors at the same high school and have been dating for over a year. I'm 5'9 and 175-180 lbs and an athlete. He's 6'1, 160 and a XC runner. He likes to pick me up thinking it will make me less insecure about my weight bc he knows it's always been an insecurity of mine. But watching him almost struggle to pick me up is somehow worse and makes me feel awful that I'm not lighter or smaller or whatever else. I'm scared to tell him that though because he has depression and anxiety and maybe 6 months into our relationship he almost committed suicide because of pressure he was dealing with due to other stuff. And I'm so scared that something like this could send him spiraling. Plus my dad isn't the best influence for me, being that anytime I eat a bunch, he tells me I need to stop so I don't get fat, so idk what to do. This has kind of become a rant now so I apologize for that. But long story short, how do I tell my bf it makes my insecurities worse?